net/vmw_vsock/virtio_transport_common.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * common code for virtio vsock
   4  *
   5  * Copyright (C) 2013-2015 Red Hat, Inc.
   6  * Author: Asias He <asias@redhat.com>
   7  *         Stefan Hajnoczi <stefanha@redhat.com>
   8  */
   9 #include <linux/spinlock.h>
  10 #include <linux/module.h>
  11 #include <linux/sched/signal.h>
  12 #include <linux/ctype.h>
  13 #include <linux/list.h>
  14 #include <linux/virtio_vsock.h>
  15 #include <uapi/linux/vsockmon.h>
  16
  17 #include <net/sock.h>
  18 #include <net/af_vsock.h>
  19
  20 #define CREATE_TRACE_POINTS
  21 #include <trace/events/vsock_virtio_transport_common.h>
  22
  23 /* How long to wait for graceful shutdown of a connection */
  24 #define VSOCK_CLOSE_TIMEOUT (8 * HZ)
  25
  26 /* Threshold for detecting small packets to copy */
  27 #define GOOD_COPY_LEN  128
  28
  29 static const struct virtio_transport *
  30 virtio_transport_get_ops(struct vsock_sock *vsk)
  31 {
  32         const struct vsock_transport *t = vsock_core_get_transport(vsk);
  33
  34         if (WARN_ON(!t))
  35                 return NULL;
  36
  37         return container_of(t, struct virtio_transport, transport);
  38 }
  39
  40 static struct virtio_vsock_pkt *
  41 virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
  42                            size_t len,
  43                            u32 src_cid,
  44                            u32 src_port,
  45                            u32 dst_cid,
  46                            u32 dst_port)
  47 {
  48         struct virtio_vsock_pkt *pkt;
  49         int err;
  50
  51         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
  52         if (!pkt)
  53                 return NULL;
  54
  55         pkt->hdr.type           = cpu_to_le16(info->type);
  56         pkt->hdr.op             = cpu_to_le16(info->op);
  57         pkt->hdr.src_cid        = cpu_to_le64(src_cid);
  58         pkt->hdr.dst_cid        = cpu_to_le64(dst_cid);
  59         pkt->hdr.src_port       = cpu_to_le32(src_port);
  60         pkt->hdr.dst_port       = cpu_to_le32(dst_port);
  61         pkt->hdr.flags          = cpu_to_le32(info->flags);
  62         pkt->len                = len;
  63         pkt->hdr.len            = cpu_to_le32(len);
  64         pkt->reply              = info->reply;
  65         pkt->vsk                = info->vsk;
  66
  67         if (info->msg && len > 0) {
  68                 pkt->buf = kmalloc(len, GFP_KERNEL);
  69                 if (!pkt->buf)
  70                         goto out_pkt;
  71
  72                 pkt->buf_len = len;
  73
  74                 err = memcpy_from_msg(pkt->buf, info->msg, len);
  75                 if (err)
  76                         goto out;
  77
  78                 if (msg_data_left(info->msg) == 0 &&
  79                     info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
  80                         pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
  81
  82                         if (info->msg->msg_flags & MSG_EOR)
  83                                 pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
  84                 }
  85         }
  86
  87         trace_virtio_transport_alloc_pkt(src_cid, src_port,
  88                                          dst_cid, dst_port,
  89                                          len,
  90                                          info->type,
  91                                          info->op,
  92                                          info->flags);
  93
  94         return pkt;
  95
  96 out:
  97         kfree(pkt->buf);
  98 out_pkt:
  99         kfree(pkt);
 100         return NULL;
 101 }
 102
 103 /* Packet capture */
 104 static struct sk_buff *virtio_transport_build_skb(void *opaque)
 105 {
 106         struct virtio_vsock_pkt *pkt = opaque;
 107         struct af_vsockmon_hdr *hdr;
 108         struct sk_buff *skb;
 109         size_t payload_len;
 110         void *payload_buf;
 111
 112         /* A packet could be split to fit the RX buffer, so we can retrieve
 113          * the payload length from the header and the buffer pointer taking
 114          * care of the offset in the original packet.
 115          */
 116         payload_len = le32_to_cpu(pkt->hdr.len);
 117         payload_buf = pkt->buf + pkt->off;
 118
 119         skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + payload_len,
 120                         GFP_ATOMIC);
 121         if (!skb)
 122                 return NULL;
 123
 124         hdr = skb_put(skb, sizeof(*hdr));
 125
 126         /* pkt->hdr is little-endian so no need to byteswap here */
 127         hdr->src_cid = pkt->hdr.src_cid;
 128         hdr->src_port = pkt->hdr.src_port;
 129         hdr->dst_cid = pkt->hdr.dst_cid;
 130         hdr->dst_port = pkt->hdr.dst_port;
 131
 132         hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
 133         hdr->len = cpu_to_le16(sizeof(pkt->hdr));
 134         memset(hdr->reserved, 0, sizeof(hdr->reserved));
 135
 136         switch (le16_to_cpu(pkt->hdr.op)) {
 137         case VIRTIO_VSOCK_OP_REQUEST:
 138         case VIRTIO_VSOCK_OP_RESPONSE:
 139                 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
 140                 break;
 141         case VIRTIO_VSOCK_OP_RST:
 142         case VIRTIO_VSOCK_OP_SHUTDOWN:
 143                 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
 144                 break;
 145         case VIRTIO_VSOCK_OP_RW:
 146                 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
 147                 break;
 148         case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 149         case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
 150                 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
 151                 break;
 152         default:
 153                 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
 154                 break;
 155         }
 156
 157         skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
 158
 159         if (payload_len) {
 160                 skb_put_data(skb, payload_buf, payload_len);
 161         }
 162
 163         return skb;
 164 }
 165
 166 void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
 167 {
 168         if (pkt->tap_delivered)
 169                 return;
 170
 171         vsock_deliver_tap(virtio_transport_build_skb, pkt);
 172         pkt->tap_delivered = true;
 173 }
 174 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
 175
 176 static u16 virtio_transport_get_type(struct sock *sk)
 177 {
 178         if (sk->sk_type == SOCK_STREAM)
 179                 return VIRTIO_VSOCK_TYPE_STREAM;
 180         else
 181                 return VIRTIO_VSOCK_TYPE_SEQPACKET;
 182 }
 183
 184 /* This function can only be used on connecting/connected sockets,
 185  * since a socket assigned to a transport is required.
 186  *
 187  * Do not use on listener sockets!
 188  */
 189 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
 190                                           struct virtio_vsock_pkt_info *info)
 191 {
 192         u32 src_cid, src_port, dst_cid, dst_port;
 193         const struct virtio_transport *t_ops;
 194         struct virtio_vsock_sock *vvs;
 195         struct virtio_vsock_pkt *pkt;
 196         u32 pkt_len = info->pkt_len;
 197
 198         info->type = virtio_transport_get_type(sk_vsock(vsk));
 199
 200         t_ops = virtio_transport_get_ops(vsk);
 201         if (unlikely(!t_ops))
 202                 return -EFAULT;
 203
 204         src_cid = t_ops->transport.get_local_cid();
 205         src_port = vsk->local_addr.svm_port;
 206         if (!info->remote_cid) {
 207                 dst_cid = vsk->remote_addr.svm_cid;
 208                 dst_port = vsk->remote_addr.svm_port;
 209         } else {
 210                 dst_cid = info->remote_cid;
 211                 dst_port = info->remote_port;
 212         }
 213
 214         vvs = vsk->trans;
 215
 216         /* we can send less than pkt_len bytes */
 217         if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
 218                 pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
 219
 220         /* virtio_transport_get_credit might return less than pkt_len credit */
 221         pkt_len = virtio_transport_get_credit(vvs, pkt_len);
 222
 223         /* Do not send zero length OP_RW pkt */
 224         if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
 225                 return pkt_len;
 226
 227         pkt = virtio_transport_alloc_pkt(info, pkt_len,
 228                                          src_cid, src_port,
 229                                          dst_cid, dst_port);
 230         if (!pkt) {
 231                 virtio_transport_put_credit(vvs, pkt_len);
 232                 return -ENOMEM;
 233         }
 234
 235         virtio_transport_inc_tx_pkt(vvs, pkt);
 236
 237         return t_ops->send_pkt(pkt);
 238 }
 239
 240 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 241                                         struct virtio_vsock_pkt *pkt)
 242 {
 243         if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
 244                 return false;
 245
 246         vvs->rx_bytes += pkt->len;
 247         return true;
 248 }
 249
 250 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
 251                                         struct virtio_vsock_pkt *pkt)
 252 {
 253         vvs->rx_bytes -= pkt->len;
 254         vvs->fwd_cnt += pkt->len;
 255 }
 256
 257 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
 258 {
 259         spin_lock_bh(&vvs->rx_lock);
 260         vvs->last_fwd_cnt = vvs->fwd_cnt;
 261         pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
 262         pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
 263         spin_unlock_bh(&vvs->rx_lock);
 264 }
 265 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
 266
 267 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
 268 {
 269         u32 ret;
 270
 271         spin_lock_bh(&vvs->tx_lock);
 272         ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 273         if (ret > credit)
 274                 ret = credit;
 275         vvs->tx_cnt += ret;
 276         spin_unlock_bh(&vvs->tx_lock);
 277
 278         return ret;
 279 }
 280 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
 281
 282 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
 283 {
 284         spin_lock_bh(&vvs->tx_lock);
 285         vvs->tx_cnt -= credit;
 286         spin_unlock_bh(&vvs->tx_lock);
 287 }
 288 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
 289
 290 static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
 291 {
 292         struct virtio_vsock_pkt_info info = {
 293                 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
 294                 .vsk = vsk,
 295         };
 296
 297         return virtio_transport_send_pkt_info(vsk, &info);
 298 }
 299
 300 static ssize_t
 301 virtio_transport_stream_do_peek(struct vsock_sock *vsk,
 302                                 struct msghdr *msg,
 303                                 size_t len)
 304 {
 305         struct virtio_vsock_sock *vvs = vsk->trans;
 306         struct virtio_vsock_pkt *pkt;
 307         size_t bytes, total = 0, off;
 308         int err = -EFAULT;
 309
 310         spin_lock_bh(&vvs->rx_lock);
 311
 312         list_for_each_entry(pkt, &vvs->rx_queue, list) {
 313                 off = pkt->off;
 314
 315                 if (total == len)
 316                         break;
 317
 318                 while (total < len && off < pkt->len) {
 319                         bytes = len - total;
 320                         if (bytes > pkt->len - off)
 321                                 bytes = pkt->len - off;
 322
 323                         /* sk_lock is held by caller so no one else can dequeue.
 324                          * Unlock rx_lock since memcpy_to_msg() may sleep.
 325                          */
 326                         spin_unlock_bh(&vvs->rx_lock);
 327
 328                         err = memcpy_to_msg(msg, pkt->buf + off, bytes);
 329                         if (err)
 330                                 goto out;
 331
 332                         spin_lock_bh(&vvs->rx_lock);
 333
 334                         total += bytes;
 335                         off += bytes;
 336                 }
 337         }
 338
 339         spin_unlock_bh(&vvs->rx_lock);
 340
 341         return total;
 342
 343 out:
 344         if (total)
 345                 err = total;
 346         return err;
 347 }
 348
 349 static ssize_t
 350 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
 351                                    struct msghdr *msg,
 352                                    size_t len)
 353 {
 354         struct virtio_vsock_sock *vvs = vsk->trans;
 355         struct virtio_vsock_pkt *pkt;
 356         size_t bytes, total = 0;
 357         u32 free_space;
 358         int err = -EFAULT;
 359
 360         spin_lock_bh(&vvs->rx_lock);
 361         while (total < len && !list_empty(&vvs->rx_queue)) {
 362                 pkt = list_first_entry(&vvs->rx_queue,
 363                                        struct virtio_vsock_pkt, list);
 364
 365                 bytes = len - total;
 366                 if (bytes > pkt->len - pkt->off)
 367                         bytes = pkt->len - pkt->off;
 368
 369                 /* sk_lock is held by caller so no one else can dequeue.
 370                  * Unlock rx_lock since memcpy_to_msg() may sleep.
 371                  */
 372                 spin_unlock_bh(&vvs->rx_lock);
 373
 374                 err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
 375                 if (err)
 376                         goto out;
 377
 378                 spin_lock_bh(&vvs->rx_lock);
 379
 380                 total += bytes;
 381                 pkt->off += bytes;
 382                 if (pkt->off == pkt->len) {
 383                         virtio_transport_dec_rx_pkt(vvs, pkt);
 384                         list_del(&pkt->list);
 385                         virtio_transport_free_pkt(pkt);
 386                 }
 387         }
 388
 389         free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
 390
 391         spin_unlock_bh(&vvs->rx_lock);
 392
 393         /* To reduce the number of credit update messages,
 394          * don't update credits as long as lots of space is available.
 395          * Note: the limit chosen here is arbitrary. Setting the limit
 396          * too high causes extra messages. Too low causes transmitter
 397          * stalls. As stalls are in theory more expensive than extra
 398          * messages, we set the limit to a high value. TODO: experiment
 399          * with different values.
 400          */
 401         if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
 402                 virtio_transport_send_credit_update(vsk);
 403
 404         return total;
 405
 406 out:
 407         if (total)
 408                 err = total;
 409         return err;
 410 }
 411
 412 static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
 413                                                  struct msghdr *msg,
 414                                                  int flags)
 415 {
 416         struct virtio_vsock_sock *vvs = vsk->trans;
 417         struct virtio_vsock_pkt *pkt;
 418         int dequeued_len = 0;
 419         size_t user_buf_len = msg_data_left(msg);
 420         bool msg_ready = false;
 421
 422         spin_lock_bh(&vvs->rx_lock);
 423
 424         if (vvs->msg_count == 0) {
 425                 spin_unlock_bh(&vvs->rx_lock);
 426                 return 0;
 427         }
 428
 429         while (!msg_ready) {
 430                 pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list);
 431
 432                 if (dequeued_len >= 0) {
 433                         size_t pkt_len;
 434                         size_t bytes_to_copy;
 435
 436                         pkt_len = (size_t)le32_to_cpu(pkt->hdr.len);
 437                         bytes_to_copy = min(user_buf_len, pkt_len);
 438
 439                         if (bytes_to_copy) {
 440                                 int err;
 441
 442                                 /* sk_lock is held by caller so no one else can dequeue.
 443                                  * Unlock rx_lock since memcpy_to_msg() may sleep.
 444                                  */
 445                                 spin_unlock_bh(&vvs->rx_lock);
 446
 447                                 err = memcpy_to_msg(msg, pkt->buf, bytes_to_copy);
 448                                 if (err) {
 449                                         /* Copy of message failed. Rest of
 450                                          * fragments will be freed without copy.
 451                                          */
 452                                         dequeued_len = err;
 453                                 } else {
 454                                         user_buf_len -= bytes_to_copy;
 455                                 }
 456
 457                                 spin_lock_bh(&vvs->rx_lock);
 458                         }
 459
 460                         if (dequeued_len >= 0)
 461                                 dequeued_len += pkt_len;
 462                 }
 463
 464                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
 465                         msg_ready = true;
 466                         vvs->msg_count--;
 467
 468                         if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
 469                                 msg->msg_flags |= MSG_EOR;
 470                 }
 471
 472                 virtio_transport_dec_rx_pkt(vvs, pkt);
 473                 list_del(&pkt->list);
 474                 virtio_transport_free_pkt(pkt);
 475         }
 476
 477         spin_unlock_bh(&vvs->rx_lock);
 478
 479         virtio_transport_send_credit_update(vsk);
 480
 481         return dequeued_len;
 482 }
 483
 484 ssize_t
 485 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
 486                                 struct msghdr *msg,
 487                                 size_t len, int flags)
 488 {
 489         if (flags & MSG_PEEK)
 490                 return virtio_transport_stream_do_peek(vsk, msg, len);
 491         else
 492                 return virtio_transport_stream_do_dequeue(vsk, msg, len);
 493 }
 494 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
 495
 496 ssize_t
 497 virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
 498                                    struct msghdr *msg,
 499                                    int flags)
 500 {
 501         if (flags & MSG_PEEK)
 502                 return -EOPNOTSUPP;
 503
 504         return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
 505 }
 506 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
 507
 508 int
 509 virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
 510                                    struct msghdr *msg,
 511                                    size_t len)
 512 {
 513         struct virtio_vsock_sock *vvs = vsk->trans;
 514
 515         spin_lock_bh(&vvs->tx_lock);
 516
 517         if (len > vvs->peer_buf_alloc) {
 518                 spin_unlock_bh(&vvs->tx_lock);
 519                 return -EMSGSIZE;
 520         }
 521
 522         spin_unlock_bh(&vvs->tx_lock);
 523
 524         return virtio_transport_stream_enqueue(vsk, msg, len);
 525 }
 526 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
 527
 528 int
 529 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
 530                                struct msghdr *msg,
 531                                size_t len, int flags)
 532 {
 533         return -EOPNOTSUPP;
 534 }
 535 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
 536
 537 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
 538 {
 539         struct virtio_vsock_sock *vvs = vsk->trans;
 540         s64 bytes;
 541
 542         spin_lock_bh(&vvs->rx_lock);
 543         bytes = vvs->rx_bytes;
 544         spin_unlock_bh(&vvs->rx_lock);
 545
 546         return bytes;
 547 }
 548 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
 549
 550 u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
 551 {
 552         struct virtio_vsock_sock *vvs = vsk->trans;
 553         u32 msg_count;
 554
 555         spin_lock_bh(&vvs->rx_lock);
 556         msg_count = vvs->msg_count;
 557         spin_unlock_bh(&vvs->rx_lock);
 558
 559         return msg_count;
 560 }
 561 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
 562
 563 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
 564 {
 565         struct virtio_vsock_sock *vvs = vsk->trans;
 566         s64 bytes;
 567
 568         bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 569         if (bytes < 0)
 570                 bytes = 0;
 571
 572         return bytes;
 573 }
 574
 575 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
 576 {
 577         struct virtio_vsock_sock *vvs = vsk->trans;
 578         s64 bytes;
 579
 580         spin_lock_bh(&vvs->tx_lock);
 581         bytes = virtio_transport_has_space(vsk);
 582         spin_unlock_bh(&vvs->tx_lock);
 583
 584         return bytes;
 585 }
 586 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
 587
 588 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 589                                     struct vsock_sock *psk)
 590 {
 591         struct virtio_vsock_sock *vvs;
 592
 593         vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
 594         if (!vvs)
 595                 return -ENOMEM;
 596
 597         vsk->trans = vvs;
 598         vvs->vsk = vsk;
 599         if (psk && psk->trans) {
 600                 struct virtio_vsock_sock *ptrans = psk->trans;
 601
 602                 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 603         }
 604
 605         if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
 606                 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
 607
 608         vvs->buf_alloc = vsk->buffer_size;
 609
 610         spin_lock_init(&vvs->rx_lock);
 611         spin_lock_init(&vvs->tx_lock);
 612         INIT_LIST_HEAD(&vvs->rx_queue);
 613
 614         return 0;
 615 }
 616 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
 617
 618 /* sk_lock held by the caller */
 619 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
 620 {
 621         struct virtio_vsock_sock *vvs = vsk->trans;
 622
 623         if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 624                 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 625
 626         vvs->buf_alloc = *val;
 627
 628         virtio_transport_send_credit_update(vsk);
 629 }
 630 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
 631
 632 int
 633 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
 634                                 size_t target,
 635                                 bool *data_ready_now)
 636 {
 637         *data_ready_now = vsock_stream_has_data(vsk) >= target;
 638
 639         return 0;
 640 }
 641 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
 642
 643 int
 644 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
 645                                  size_t target,
 646                                  bool *space_avail_now)
 647 {
 648         s64 free_space;
 649
 650         free_space = vsock_stream_has_space(vsk);
 651         if (free_space > 0)
 652                 *space_avail_now = true;
 653         else if (free_space == 0)
 654                 *space_avail_now = false;
 655
 656         return 0;
 657 }
 658 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
 659
 660 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
 661         size_t target, struct vsock_transport_recv_notify_data *data)
 662 {
 663         return 0;
 664 }
 665 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
 666
 667 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
 668         size_t target, struct vsock_transport_recv_notify_data *data)
 669 {
 670         return 0;
 671 }
 672 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
 673
 674 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
 675         size_t target, struct vsock_transport_recv_notify_data *data)
 676 {
 677         return 0;
 678 }
 679 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
 680
 681 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
 682         size_t target, ssize_t copied, bool data_read,
 683         struct vsock_transport_recv_notify_data *data)
 684 {
 685         return 0;
 686 }
 687 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
 688
 689 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
 690         struct vsock_transport_send_notify_data *data)
 691 {
 692         return 0;
 693 }
 694 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
 695
 696 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
 697         struct vsock_transport_send_notify_data *data)
 698 {
 699         return 0;
 700 }
 701 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
 702
 703 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
 704         struct vsock_transport_send_notify_data *data)
 705 {
 706         return 0;
 707 }
 708 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
 709
 710 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
 711         ssize_t written, struct vsock_transport_send_notify_data *data)
 712 {
 713         return 0;
 714 }
 715 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
 716
 717 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
 718 {
 719         return vsk->buffer_size;
 720 }
 721 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
 722
 723 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 724 {
 725         return true;
 726 }
 727 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 728
 729 bool virtio_transport_stream_allow(u32 cid, u32 port)
 730 {
 731         return true;
 732 }
 733 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 734
 735 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 736                                 struct sockaddr_vm *addr)
 737 {
 738         return -EOPNOTSUPP;
 739 }
 740 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 741
 742 bool virtio_transport_dgram_allow(u32 cid, u32 port)
 743 {
 744         return false;
 745 }
 746 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
 747
 748 int virtio_transport_connect(struct vsock_sock *vsk)
 749 {
 750         struct virtio_vsock_pkt_info info = {
 751                 .op = VIRTIO_VSOCK_OP_REQUEST,
 752                 .vsk = vsk,
 753         };
 754
 755         return virtio_transport_send_pkt_info(vsk, &info);
 756 }
 757 EXPORT_SYMBOL_GPL(virtio_transport_connect);
 758
 759 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
 760 {
 761         struct virtio_vsock_pkt_info info = {
 762                 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
 763                 .flags = (mode & RCV_SHUTDOWN ?
 764                           VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
 765                          (mode & SEND_SHUTDOWN ?
 766                           VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
 767                 .vsk = vsk,
 768         };
 769
 770         return virtio_transport_send_pkt_info(vsk, &info);
 771 }
 772 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
 773
 774 int
 775 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
 776                                struct sockaddr_vm *remote_addr,
 777                                struct msghdr *msg,
 778                                size_t dgram_len)
 779 {
 780         return -EOPNOTSUPP;
 781 }
 782 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
 783
 784 ssize_t
 785 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
 786                                 struct msghdr *msg,
 787                                 size_t len)
 788 {
 789         struct virtio_vsock_pkt_info info = {
 790                 .op = VIRTIO_VSOCK_OP_RW,
 791                 .msg = msg,
 792                 .pkt_len = len,
 793                 .vsk = vsk,
 794         };
 795
 796         return virtio_transport_send_pkt_info(vsk, &info);
 797 }
 798 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
 799
 800 void virtio_transport_destruct(struct vsock_sock *vsk)
 801 {
 802         struct virtio_vsock_sock *vvs = vsk->trans;
 803
 804         kfree(vvs);
 805 }
 806 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
 807
 808 static int virtio_transport_reset(struct vsock_sock *vsk,
 809                                   struct virtio_vsock_pkt *pkt)
 810 {
 811         struct virtio_vsock_pkt_info info = {
 812                 .op = VIRTIO_VSOCK_OP_RST,
 813                 .reply = !!pkt,
 814                 .vsk = vsk,
 815         };
 816
 817         /* Send RST only if the original pkt is not a RST pkt */
 818         if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 819                 return 0;
 820
 821         return virtio_transport_send_pkt_info(vsk, &info);
 822 }
 823
 824 /* Normally packets are associated with a socket.  There may be no socket if an
 825  * attempt was made to connect to a socket that does not exist.
 826  */
 827 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
 828                                           struct virtio_vsock_pkt *pkt)
 829 {
 830         struct virtio_vsock_pkt *reply;
 831         struct virtio_vsock_pkt_info info = {
 832                 .op = VIRTIO_VSOCK_OP_RST,
 833                 .type = le16_to_cpu(pkt->hdr.type),
 834                 .reply = true,
 835         };
 836
 837         /* Send RST only if the original pkt is not a RST pkt */
 838         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 839                 return 0;
 840
 841         reply = virtio_transport_alloc_pkt(&info, 0,
 842                                            le64_to_cpu(pkt->hdr.dst_cid),
 843                                            le32_to_cpu(pkt->hdr.dst_port),
 844                                            le64_to_cpu(pkt->hdr.src_cid),
 845                                            le32_to_cpu(pkt->hdr.src_port));
 846         if (!reply)
 847                 return -ENOMEM;
 848
 849         if (!t) {
 850                 virtio_transport_free_pkt(reply);
 851                 return -ENOTCONN;
 852         }
 853
 854         return t->send_pkt(reply);
 855 }
 856
 857 /* This function should be called with sk_lock held and SOCK_DONE set */
 858 static void virtio_transport_remove_sock(struct vsock_sock *vsk)
 859 {
 860         struct virtio_vsock_sock *vvs = vsk->trans;
 861         struct virtio_vsock_pkt *pkt, *tmp;
 862
 863         /* We don't need to take rx_lock, as the socket is closing and we are
 864          * removing it.
 865          */
 866         list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
 867                 list_del(&pkt->list);
 868                 virtio_transport_free_pkt(pkt);
 869         }
 870
 871         vsock_remove_sock(vsk);
 872 }
 873
 874 static void virtio_transport_wait_close(struct sock *sk, long timeout)
 875 {
 876         if (timeout) {
 877                 DEFINE_WAIT_FUNC(wait, woken_wake_function);
 878
 879                 add_wait_queue(sk_sleep(sk), &wait);
 880
 881                 do {
 882                         if (sk_wait_event(sk, &timeout,
 883                                           sock_flag(sk, SOCK_DONE), &wait))
 884                                 break;
 885                 } while (!signal_pending(current) && timeout);
 886
 887                 remove_wait_queue(sk_sleep(sk), &wait);
 888         }
 889 }
 890
 891 static void virtio_transport_do_close(struct vsock_sock *vsk,
 892                                       bool cancel_timeout)
 893 {
 894         struct sock *sk = sk_vsock(vsk);
 895
 896         sock_set_flag(sk, SOCK_DONE);
 897         vsk->peer_shutdown = SHUTDOWN_MASK;
 898         if (vsock_stream_has_data(vsk) <= 0)
 899                 sk->sk_state = TCP_CLOSING;
 900         sk->sk_state_change(sk);
 901
 902         if (vsk->close_work_scheduled &&
 903             (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
 904                 vsk->close_work_scheduled = false;
 905
 906                 virtio_transport_remove_sock(vsk);
 907
 908                 /* Release refcnt obtained when we scheduled the timeout */
 909                 sock_put(sk);
 910         }
 911 }
 912
 913 static void virtio_transport_close_timeout(struct work_struct *work)
 914 {
 915         struct vsock_sock *vsk =
 916                 container_of(work, struct vsock_sock, close_work.work);
 917         struct sock *sk = sk_vsock(vsk);
 918
 919         sock_hold(sk);
 920         lock_sock(sk);
 921
 922         if (!sock_flag(sk, SOCK_DONE)) {
 923                 (void)virtio_transport_reset(vsk, NULL);
 924
 925                 virtio_transport_do_close(vsk, false);
 926         }
 927
 928         vsk->close_work_scheduled = false;
 929
 930         release_sock(sk);
 931         sock_put(sk);
 932 }
 933
 934 /* User context, vsk->sk is locked */
 935 static bool virtio_transport_close(struct vsock_sock *vsk)
 936 {
 937         struct sock *sk = &vsk->sk;
 938
 939         if (!(sk->sk_state == TCP_ESTABLISHED ||
 940               sk->sk_state == TCP_CLOSING))
 941                 return true;
 942
 943         /* Already received SHUTDOWN from peer, reply with RST */
 944         if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
 945                 (void)virtio_transport_reset(vsk, NULL);
 946                 return true;
 947         }
 948
 949         if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
 950                 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
 951
 952         if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
 953                 virtio_transport_wait_close(sk, sk->sk_lingertime);
 954
 955         if (sock_flag(sk, SOCK_DONE)) {
 956                 return true;
 957         }
 958
 959         sock_hold(sk);
 960         INIT_DELAYED_WORK(&vsk->close_work,
 961                           virtio_transport_close_timeout);
 962         vsk->close_work_scheduled = true;
 963         schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
 964         return false;
 965 }
 966
 967 void virtio_transport_release(struct vsock_sock *vsk)
 968 {
 969         struct sock *sk = &vsk->sk;
 970         bool remove_sock = true;
 971
 972         if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
 973                 remove_sock = virtio_transport_close(vsk);
 974
 975         if (remove_sock) {
 976                 sock_set_flag(sk, SOCK_DONE);
 977                 virtio_transport_remove_sock(vsk);
 978         }
 979 }
 980 EXPORT_SYMBOL_GPL(virtio_transport_release);
 981
 982 static int
 983 virtio_transport_recv_connecting(struct sock *sk,
 984                                  struct virtio_vsock_pkt *pkt)
 985 {
 986         struct vsock_sock *vsk = vsock_sk(sk);
 987         int err;
 988         int skerr;
 989
 990         switch (le16_to_cpu(pkt->hdr.op)) {
 991         case VIRTIO_VSOCK_OP_RESPONSE:
 992                 sk->sk_state = TCP_ESTABLISHED;
 993                 sk->sk_socket->state = SS_CONNECTED;
 994                 vsock_insert_connected(vsk);
 995                 sk->sk_state_change(sk);
 996                 break;
 997         case VIRTIO_VSOCK_OP_INVALID:
 998                 break;
 999         case VIRTIO_VSOCK_OP_RST:
1000                 skerr = ECONNRESET;
1001                 err = 0;
1002                 goto destroy;
1003         default:
1004                 skerr = EPROTO;
1005                 err = -EINVAL;
1006                 goto destroy;
1007         }
1008         return 0;
1009
1010 destroy:
1011         virtio_transport_reset(vsk, pkt);
1012         sk->sk_state = TCP_CLOSE;
1013         sk->sk_err = skerr;
1014         sk_error_report(sk);
1015         return err;
1016 }
1017
1018 static void
1019 virtio_transport_recv_enqueue(struct vsock_sock *vsk,
1020                               struct virtio_vsock_pkt *pkt)
1021 {
1022         struct virtio_vsock_sock *vvs = vsk->trans;
1023         bool can_enqueue, free_pkt = false;
1024
1025         pkt->len = le32_to_cpu(pkt->hdr.len);
1026         pkt->off = 0;
1027
1028         spin_lock_bh(&vvs->rx_lock);
1029
1030         can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
1031         if (!can_enqueue) {
1032                 free_pkt = true;
1033                 goto out;
1034         }
1035
1036         if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)
1037                 vvs->msg_count++;
1038
1039         /* Try to copy small packets into the buffer of last packet queued,
1040          * to avoid wasting memory queueing the entire buffer with a small
1041          * payload.
1042          */
1043         if (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
1044                 struct virtio_vsock_pkt *last_pkt;
1045
1046                 last_pkt = list_last_entry(&vvs->rx_queue,
1047                                            struct virtio_vsock_pkt, list);
1048
1049                 /* If there is space in the last packet queued, we copy the
1050                  * new packet in its buffer. We avoid this if the last packet
1051                  * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
1052                  * delimiter of SEQPACKET message, so 'pkt' is the first packet
1053                  * of a new message.
1054                  */
1055                 if ((pkt->len <= last_pkt->buf_len - last_pkt->len) &&
1056                     !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)) {
1057                         memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
1058                                pkt->len);
1059                         last_pkt->len += pkt->len;
1060                         free_pkt = true;
1061                         last_pkt->hdr.flags |= pkt->hdr.flags;
1062                         goto out;
1063                 }
1064         }
1065
1066         list_add_tail(&pkt->list, &vvs->rx_queue);
1067
1068 out:
1069         spin_unlock_bh(&vvs->rx_lock);
1070         if (free_pkt)
1071                 virtio_transport_free_pkt(pkt);
1072 }
1073
1074 static int
1075 virtio_transport_recv_connected(struct sock *sk,
1076                                 struct virtio_vsock_pkt *pkt)
1077 {
1078         struct vsock_sock *vsk = vsock_sk(sk);
1079         int err = 0;
1080
1081         switch (le16_to_cpu(pkt->hdr.op)) {
1082         case VIRTIO_VSOCK_OP_RW:
1083                 virtio_transport_recv_enqueue(vsk, pkt);
1084                 vsock_data_ready(sk);
1085                 return err;
1086         case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
1087                 virtio_transport_send_credit_update(vsk);
1088                 break;
1089         case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
1090                 sk->sk_write_space(sk);
1091                 break;
1092         case VIRTIO_VSOCK_OP_SHUTDOWN:
1093                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
1094                         vsk->peer_shutdown |= RCV_SHUTDOWN;
1095                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
1096                         vsk->peer_shutdown |= SEND_SHUTDOWN;
1097                 if (vsk->peer_shutdown == SHUTDOWN_MASK &&
1098                     vsock_stream_has_data(vsk) <= 0 &&
1099                     !sock_flag(sk, SOCK_DONE)) {
1100                         (void)virtio_transport_reset(vsk, NULL);
1101
1102                         virtio_transport_do_close(vsk, true);
1103                 }
1104                 if (le32_to_cpu(pkt->hdr.flags))
1105                         sk->sk_state_change(sk);
1106                 break;
1107         case VIRTIO_VSOCK_OP_RST:
1108                 virtio_transport_do_close(vsk, true);
1109                 break;
1110         default:
1111                 err = -EINVAL;
1112                 break;
1113         }
1114
1115         virtio_transport_free_pkt(pkt);
1116         return err;
1117 }
1118
1119 static void
1120 virtio_transport_recv_disconnecting(struct sock *sk,
1121                                     struct virtio_vsock_pkt *pkt)
1122 {
1123         struct vsock_sock *vsk = vsock_sk(sk);
1124
1125         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
1126                 virtio_transport_do_close(vsk, true);
1127 }
1128
1129 static int
1130 virtio_transport_send_response(struct vsock_sock *vsk,
1131                                struct virtio_vsock_pkt *pkt)
1132 {
1133         struct virtio_vsock_pkt_info info = {
1134                 .op = VIRTIO_VSOCK_OP_RESPONSE,
1135                 .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
1136                 .remote_port = le32_to_cpu(pkt->hdr.src_port),
1137                 .reply = true,
1138                 .vsk = vsk,
1139         };
1140
1141         return virtio_transport_send_pkt_info(vsk, &info);
1142 }
1143
1144 static bool virtio_transport_space_update(struct sock *sk,
1145                                           struct virtio_vsock_pkt *pkt)
1146 {
1147         struct vsock_sock *vsk = vsock_sk(sk);
1148         struct virtio_vsock_sock *vvs = vsk->trans;
1149         bool space_available;
1150
1151         /* Listener sockets are not associated with any transport, so we are
1152          * not able to take the state to see if there is space available in the
1153          * remote peer, but since they are only used to receive requests, we
1154          * can assume that there is always space available in the other peer.
1155          */
1156         if (!vvs)
1157                 return true;
1158
1159         /* buf_alloc and fwd_cnt is always included in the hdr */
1160         spin_lock_bh(&vvs->tx_lock);
1161         vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
1162         vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
1163         space_available = virtio_transport_has_space(vsk);
1164         spin_unlock_bh(&vvs->tx_lock);
1165         return space_available;
1166 }
1167
1168 /* Handle server socket */
1169 static int
1170 virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
1171                              struct virtio_transport *t)
1172 {
1173         struct vsock_sock *vsk = vsock_sk(sk);
1174         struct vsock_sock *vchild;
1175         struct sock *child;
1176         int ret;
1177
1178         if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
1179                 virtio_transport_reset_no_sock(t, pkt);
1180                 return -EINVAL;
1181         }
1182
1183         if (sk_acceptq_is_full(sk)) {
1184                 virtio_transport_reset_no_sock(t, pkt);
1185                 return -ENOMEM;
1186         }
1187
1188         child = vsock_create_connected(sk);
1189         if (!child) {
1190                 virtio_transport_reset_no_sock(t, pkt);
1191                 return -ENOMEM;
1192         }
1193
1194         sk_acceptq_added(sk);
1195
1196         lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1197
1198         child->sk_state = TCP_ESTABLISHED;
1199
1200         vchild = vsock_sk(child);
1201         vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
1202                         le32_to_cpu(pkt->hdr.dst_port));
1203         vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
1204                         le32_to_cpu(pkt->hdr.src_port));
1205
1206         ret = vsock_assign_transport(vchild, vsk);
1207         /* Transport assigned (looking at remote_addr) must be the same
1208          * where we received the request.
1209          */
1210         if (ret || vchild->transport != &t->transport) {
1211                 release_sock(child);
1212                 virtio_transport_reset_no_sock(t, pkt);
1213                 sock_put(child);
1214                 return ret;
1215         }
1216
1217         if (virtio_transport_space_update(child, pkt))
1218                 child->sk_write_space(child);
1219
1220         vsock_insert_connected(vchild);
1221         vsock_enqueue_accept(sk, child);
1222         virtio_transport_send_response(vchild, pkt);
1223
1224         release_sock(child);
1225
1226         sk->sk_data_ready(sk);
1227         return 0;
1228 }
1229
1230 static bool virtio_transport_valid_type(u16 type)
1231 {
1232         return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
1233                (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
1234 }
1235
1236 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1237  * lock.
1238  */
1239 void virtio_transport_recv_pkt(struct virtio_transport *t,
1240                                struct virtio_vsock_pkt *pkt)
1241 {
1242         struct sockaddr_vm src, dst;
1243         struct vsock_sock *vsk;
1244         struct sock *sk;
1245         bool space_available;
1246
1247         vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
1248                         le32_to_cpu(pkt->hdr.src_port));
1249         vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
1250                         le32_to_cpu(pkt->hdr.dst_port));
1251
1252         trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1253                                         dst.svm_cid, dst.svm_port,
1254                                         le32_to_cpu(pkt->hdr.len),
1255                                         le16_to_cpu(pkt->hdr.type),
1256                                         le16_to_cpu(pkt->hdr.op),
1257                                         le32_to_cpu(pkt->hdr.flags),
1258                                         le32_to_cpu(pkt->hdr.buf_alloc),
1259                                         le32_to_cpu(pkt->hdr.fwd_cnt));
1260
1261         if (!virtio_transport_valid_type(le16_to_cpu(pkt->hdr.type))) {
1262                 (void)virtio_transport_reset_no_sock(t, pkt);
1263                 goto free_pkt;
1264         }
1265
1266         /* The socket must be in connected or bound table
1267          * otherwise send reset back
1268          */
1269         sk = vsock_find_connected_socket(&src, &dst);
1270         if (!sk) {
1271                 sk = vsock_find_bound_socket(&dst);
1272                 if (!sk) {
1273                         (void)virtio_transport_reset_no_sock(t, pkt);
1274                         goto free_pkt;
1275                 }
1276         }
1277
1278         if (virtio_transport_get_type(sk) != le16_to_cpu(pkt->hdr.type)) {
1279                 (void)virtio_transport_reset_no_sock(t, pkt);
1280                 sock_put(sk);
1281                 goto free_pkt;
1282         }
1283
1284         vsk = vsock_sk(sk);
1285
1286         lock_sock(sk);
1287
1288         /* Check if sk has been closed before lock_sock */
1289         if (sock_flag(sk, SOCK_DONE)) {
1290                 (void)virtio_transport_reset_no_sock(t, pkt);
1291                 release_sock(sk);
1292                 sock_put(sk);
1293                 goto free_pkt;
1294         }
1295
1296         space_available = virtio_transport_space_update(sk, pkt);
1297
1298         /* Update CID in case it has changed after a transport reset event */
1299         if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
1300                 vsk->local_addr.svm_cid = dst.svm_cid;
1301
1302         if (space_available)
1303                 sk->sk_write_space(sk);
1304
1305         switch (sk->sk_state) {
1306         case TCP_LISTEN:
1307                 virtio_transport_recv_listen(sk, pkt, t);
1308                 virtio_transport_free_pkt(pkt);
1309                 break;
1310         case TCP_SYN_SENT:
1311                 virtio_transport_recv_connecting(sk, pkt);
1312                 virtio_transport_free_pkt(pkt);
1313                 break;
1314         case TCP_ESTABLISHED:
1315                 virtio_transport_recv_connected(sk, pkt);
1316                 break;
1317         case TCP_CLOSING:
1318                 virtio_transport_recv_disconnecting(sk, pkt);
1319                 virtio_transport_free_pkt(pkt);
1320                 break;
1321         default:
1322                 (void)virtio_transport_reset_no_sock(t, pkt);
1323                 virtio_transport_free_pkt(pkt);
1324                 break;
1325         }
1326
1327         release_sock(sk);
1328
1329         /* Release refcnt obtained when we fetched this socket out of the
1330          * bound or connected list.
1331          */
1332         sock_put(sk);
1333         return;
1334
1335 free_pkt:
1336         virtio_transport_free_pkt(pkt);
1337 }
1338 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1339
1340 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
1341 {
1342         kvfree(pkt->buf);
1343         kfree(pkt);
1344 }
1345 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
1346
1347 MODULE_LICENSE("GPL v2");
1348 MODULE_AUTHOR("Asias He");
1349 MODULE_DESCRIPTION("common code for virtio vsock");